It sounds like something you’d read in one of those pop up ads that don’t go away: “Exercise not only appears to keep skin younger, it may also even reverse skin aging in people who start exercising late in life.” In fact, the words come from New York Times’ health columnist Gretchen Reynolds, who points us to some interesting research conducted at McMaster University. Scientists at the school worked with 29 men and women, from 20 to 84 years old. About half were active, meaning they did at least three hours of moderate or vigorous physical activity a week, and the others did less than one hour a week. Seeking skin that hadn’t been exposed to sun, the researchers ended up examining skin from the participants’ buttocks, where they found a big difference in the skin of those who exercised and those who didn’t. Reynold reports that “after age 40, the men and women who exercised frequently had markedly thinner, healthier stratum corneums and thicker dermis layers in their skin. Their skin was much closer in composition to that of the 20- and 30-year-olds than to that of others of their age, even if they were past age 65.” Wait there’s more: the researchers next asked some of the non-exercisers over the age of 65 to start jogging or cycling twice a week at a moderately strenuous pace, equivalent to at least 65 percent of their maximum aerobic capacity for 30 minutes. After three months, the researchers found, their skin looked very similar to those of 20- to 40-year-olds. Read more in the New York Times.